The phase sequence is clockwise or anti-clockwise. The only time when a change may happen is when the cables get transposed when a transformer is replaced or a generator is inserted and appropiate before and after tests were not done.
Get a phasesequence meter ( for continuous duty ) with optical indicators and sense these with an optocoupler to detect rotation and trigger your alarm or relay.
The phase sequence is clockwise or anti-clockwise. The only time when a change may happen is when the cables get transposed when a transformer is replaced or a generator is inserted and appropiate before and after tests were not done.
Get a phasesequence meter ( for continuous duty ) with optical indicators and sense these with an optocoupler to detect rotation and trigger your alarm or relay.
I wanted to know , on what principle this stuff work? I have a blower in the workshop, which is driven by the 3phase motor. Some time the phase sequence get change(R Y B) due to other experiment done inside. This is making the blower to work as suction device. I wanted to sense the phase sequence and if the phases are not in the correct sequence ( ie RBY, YRB,BRY etc) , i need to de-energize the relay connected to the motor.
Could you please tell me , is there any other easy method to do this inaddition to the one i mentioned earlier ?
A simple way would be 2 zero crossing detectors on the R & B phases. The R would trigger a 10mS monostable, if the B detector triggers before the monostable times out then the phases are wrong. Another very good indicator is a fan that runs backward.
How on earth do the phases get changed in the first place?